Royal Enfield Genuine Tab Washer – Original Gearbox Front Sprocket Lock Washer for UCE Models (Part No. 570247/D)

The Royal Enfield Genuine Tab Washer (Part No. 570247/D) is a factory-original mechanical safety locking fastener engineered explicitly for Royal Enfield Unit Construction Engine (UCE) motorcycles. Positioned directly on the gearbox output shaft, this specialized washer sits flush against the front drive sprocket (output chain sprocket) before the main retention nut is torqued down. Its primary mechanical function is to provide a positive, fail-safe lock that prevents the sprocket nut from backing off or spinning loose under continuous engine torque and violent chain snapped pulls.

As showcased in the high-definition product view in image_a192ab.png and verified by the official factory retail label in image_a1926e.png, this OEM component features an internally splined ring matched with prominent external locking tabs. Once the main sprocket nut is tightened to its factory torque spec, one or more of these outer metal tabs are physically bent upward against the flat sides of the nut using a chisel or punch. This physical barrier mechanically anchors the nut, ensuring your final drive sprocket remains absolutely secure during high-speed highway touring.

Key Features:

• 100% Royal Enfield Genuine Spares: Authentic factory-original drive train component manufactured to meet strict OEM steel composition and malleable thickness standards.

• Internal Splined Drive Alignment: Features a precision-cut internal multi-tooth spline profile, as highlighted in image_a192ab.png, that interlocks perfectly with the gearbox countershaft to prevent the washer itself from rotating.

• Bendable High-Tensile Lock Tabs: Forged from a specialized malleable structural steel alloy that can take tight, 90-degree folds against the sprocket nut flats without cracking or fatiguing.

• Critical Countershaft Thread Protection: Acts as a sacrificial mechanical stabilizer, absorbing rotational shocks and preventing catastrophic thread stripping on the expensive gearbox output shaft.

• Direct UCE Transmission Fitment: Engineered with the precise inner diameter and spline count required to drop straight onto standard 350cc and 500cc UCE countershafts without loose tolerances.

Technical Specifications:

• Brand: Royal Enfield Genuine Parts

• Part Number: 570247/D

• Component Type: Tab Washer / Front Sprocket Lock Washer

• Material: Heavy-Duty Malleable Carbon Steel

• Pricing Notice: While the commercial wholesale outer pack carries a net quantity of 5 units with a total retail price of ₹125.00, it is distributed individually at a unit sale price of ₹25.00 per piece, as officially documented on the manufacturer label in image_a1926e.png.

• Country of Origin: India

Motorcycle Compatibility

• Royal Enfield Classic Series (UCE Generations): Fits all carbureted and Electronic Fuel Injection (EFI) Classic 350cc and Classic 500cc models built with the integrated Unit Construction Engine.

• Royal Enfield Bullet Series (UCE): Standard fitment for the Bullet 350 Twinspark, Bullet Electra, and Bullet 500 UCE variants.

• Royal Enfield Thunderbird Series (UCE): Perfectly matches the gearbox output shaft geometry on Thunderbird 350 and Thunderbird 500 twin-spark models.

• Compatibility Note: This splined tab washer is designed exclusively for the countershaft profile of traditional UCE engines. It will not fit vintage Cast Iron models with separate gearboxes or modern Next-Gen J-Series engines (like the Meteor, Hunter, or Reborn Classic) which utilize a completely redesigned final drive hardware interface.